Yeah, pretty much the only time you see an XTi with a Pro Photographer, is for a back-up camera, even then, not verry likely. Most use 30 or 40D's as their backup (some even have 2-3 1DsMKIII's
/jeliousy)
As Irishwistle said, it's the person behind the eye-piece that makes the difference, not the camera. The camera just makes it a little easier somtimes. And without knowledge of all the camera's settings, you have absolutly no buisness having a DSLR, because thats what they are meant for, photographers, and you cant call yourself a photographer if you dont know how to adjust settings to get that great photo.
I hate it when I have some of my friends start talking about how awsome my DSLR is, and how they have always wanted one and cant wait to get one, then not a few moments later start saying things like "what's this button do?" "what the hell is ISO?" "Shutter what?" what "does that 2.8 mean on the lense thingy?" "whats WB?" and one of my favorites..."What does that button on the front do?"(refering to the shutter button"
I have tons more stupid questions ive been asked about my camera, I cant believe to wonder what kind of questions I would get with a 1DsMKIII because there are even a couple buttons on there that I dont even know (although im sure I would be smart enough to figure it out).